<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

    <style>
        div{
            width: 1000px;
            height: 1000px;
            border: 1px solid green;/* 边框 */
            background-image: url("images/头像.jpg");
            /* 默认全部是平铺的 */
        }
        /* 水平平铺 */
        .div1{
            background-repeat: repeat-x;
        }
        /* 垂直平铺 */
        .div2{
            background-repeat: repeat-y;
        }
        /* 不平铺 */
        .div3{
            background-repeat: no-repeat;
        }
    </style>
</head>
<body>

<div class="div1"></div>
<div class="div2"></div>
<div class="div3"></div>

</body>
</html>